Federal and state environmental regulations require the operators of sanitary landfill operations to periodically cover disposed solid waste with six inches of earthen material to control disease, insects, fires, odors, blowing litter, and scavenging. For example, most jurisdictions require such covering of sanitary landfills at the end of each operating day, or at more frequent intervals if necessary. This covering requirement and the cover material is known as "daily cover" or "periodic cover" where the regulatory interval is more than one day, e.g., three days. As used herein, "daily cover" is intended to include daily and periodic cover for sanitary landfills, such as municipal solid waste (MSW) landfills, rubble landfills, land clearing debris landfills, and industrial waste landfills.
Each day's garbage, trash or rubble layer is covered at the end of the day and further garbage, trash or rubble layers are then spread directly on top of the daily cover from the previous day. In many landfill sites the soil used for the daily cover must be mined at the landfill site or purchased from an outside source and, due to the high rate of soil consumption, comprises a substantial cost item. Moreover, it has been recognized that multiple earth fill layers used in this way consume a significant volume of the valuable landfill space which might otherwise be used for receiving garbage, trash or rubble. It is well known that many communities are rapidly exhausting their available landfill acreage and it is therefore desirable to reduce the consumption rate of the available landfill volume. Accordingly, federal and state regulations allow alternative, more compressible, daily cover materials in lieu of the six inches of earthen material so long as the alternative materials provide the requisite level of protection.
One known solution to reducing the volume of municipal solid waste landfills is to shred the municipal solid waste to achieve a greater filling density in the landfill. One example of this solution is disclosed in U.S. Pat. No. 4,834,300 to Wojciechowski et al. which describes a process of reducing municipal solid waste to dry particles of a relatively small, uniform size to be mixed with the earth of a landfill for minimizing settlement and maximizing the load support capabilities of the landfill. While this process for forming a municipal solid waste landfill may be acceptable in some jurisdictions, it does not provide the daily cover required by the great majority of jurisdictions.
Some jurisdictions permit disposal of municipal solid waste in a landfill in shredded form without a requirement for daily cover. Although this method for disposal is accepted in some instances, it still has serious health and environmental drawbacks compared to landfills which require daily cover.
The prior art also does not adequately address the problem of disposing of construction and demolition debris in an efficient, useful and/or space saving manner. Rubble landfills in which construction and demolition debris is typically disposed consume a substantial volume of available landfill space. It would be desirable therefore to provide a method of recycling construction and demolition debris in a way which eliminates the need for rubble landfills and in which substantially the entire volume of construction and demolition debris can be recycled and made use of in other earth engineering applications.
Another problem not adequately addressed by the prior art is the disposal of the leachate that collects at the bottom of a landfill. At the present time, such leachate must be transported or pumped to a facility for treatment of any odiferous, toxic, hazardous and/or other wastes that may be contained in the leachate. The cost of such leachate treatment, necessarily adds to the cost of operating a landfill. It would be desirable therefore to provide a method of disposing of or recycling the landfill leachate in such a way as to minimize or eliminate the cost of treating and/or disposing of the leachate.